#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>

int main()
{
	int a = 0;
	int b = 0;
	int c = 0;
	int mid = 0;
	scanf("%d %d %d", &a, &b, &c);
	if ((a + b) > c && (a + c) > b && (b + c) > a)
		if ((a - b) < c && (a - c) < b && (b - c) < a)
			mid = 1;
	if (mid == 1)
	{
		if (a == b || b == c || a == c)
		{
			if (a == b && b == c)
				printf("Equilateral triangle!\n");
			else
			printf("Isosceles triangle!\n");
		}
		else
			printf("Ordinary triangle!\n");
	}
	else
		printf("Not a triangle!\n");

	return 0;
}